class_docstr: LightningMultiDataLoader class is used by DatasetLoader class to load multiple
  datasets and more granular. This class overrides some functions from MultiDataLoader
  to make them lightning trainer compatible
code: def __init__(
      self,
      loaders: Dict[str, DataLoader],
      iteration_strategy: iteration_strategies.IterationStrategy = None,
  ):
      super().__init__(loaders, iteration_strategy)
  
file_path: mmf/mmf/datasets/lightning_multi_dataset_loader.py
imports: import math
  from typing import Dict
  from mmf.datasets import iteration_strategies
  from mmf.datasets.multi_dataset_loader import MultiDataLoader
  from torch.utils.data import DataLoader
label_desc: Use image node_id 1 to create a new LightningMultiDataLoader object from inherited base classes: MultiDataLoader with example: obj = LightningMultiDataLoader(loaders, iteration_strategy)